The following further account may aid the description thus far given. The ovum, protected by a membrane of its own, called the amnios, descends into the uterus, where it takes its hold of the membranes already there—the decidua. It pushes its way before, as exemplified in the subjoined drawing:— [Illustration: _a_—The decidua lining the womb. _b_—Do. protecting the ovum. _c_—The upper part of the womb, where the ovum has become adherent. _d_—The ovum.] The next cut shows the advanced condition of the fœtus:— [Illustration: _a_—The womb. _b_—The liquor amnii, with the fœtus. _c_—The chorion. _d_—The decidua. _e_—The opening of the fallopian tubes.] It will answer no practical usefulness to go through the whole minutiæ of the various physiological changes that take place relative to fœtal growth from the hour of impregnation to that of delivery. What has already been detailed, has been offered to unveil a little of that singular ignorance that exists generally among non-medical persons regarding the history of themselves. “Too much learning is a dangerous thing;” and it will readily be allowed, that a sufficient idea that certain things _happen_ is oftentimes as useful as to know _how_ they happen, especially when it belongs to a department requiring much research, time, and ingenuity, thoroughly to understand, and which may chance to be foreign to our ordinary pursuit. The period consumed in gestation is forty weeks, or nine calendar months, and the time is calculated from a fortnight after the suspension of menstruation. Some married ladies pride themselves upon being able to predict to a day—to tell the precise occasion when they conceive, and which they date from some unusual sensation experienced at the particular embrace which effected the important change. Many medical men disallow that such tokens present themselves, and are opposed to the belief which many mothers entertain, that nature is so communicative; and also are skeptical of those extraordinary influences that every day furnish proofs of maternal imagination, occasioning to the burden they carry, sundry marks, malformations, and monstrosities. Examinations have found that the order of fœtal organization is somewhat as follows: the heart and large vessels, the liver and appendages, the brain, stomach, and extremities. The determination of sex and number has hitherto defied exploration. In the early months of pregnancy the womb maintains its natural position; but as it enlarges, it also emerges from the pelvis into the abdomen. The moment of its slipping out of the pelvis is termed quickening, of which most women are sensible—some fainting on the occasion, others being attacked with nausea, hysteria, and palpitation of the heart. Quickening usually occurs between the fourth and fifth month. The fœtus is then called a child—the law ordaining that, if a woman intentionally procure, or such parties as may assist in so doing, abortion or miscarriage before